Closing yield gaps: perils and possibilities for biodiversity conservation.

Increasing agricultural productivity to 'close yield gaps' creates both perils and possibilities for biodiversity conservation. Yield increases often have negative impacts on species within farmland, but at the same time could potentially make it more feasible to minimize further cropland expansion into natural habitats. We combine global data on yield gaps, projected future production of maize, rice and wheat, the distributions of birds and their estimated sensitivity to changes in crop yields to map where it might be most beneficial for bird conservation to close yield gaps as part of a land-sparing strategy, and where doing so might be most damaging. Closing yield gaps to attainable levels to meet projected demand in 2050 could potentially help spare an area equivalent to that of the Indian subcontinent. Increasing yields this much on existing farmland would inevitably reduce its biodiversity, and therefore we advocate efforts both to constrain further increases in global food demand, and to identify the least harmful ways of increasing yields. The land-sparing potential of closing yield gaps will not be realized without specific mechanisms to link yield increases to habitat protection (and restoration), and therefore we suggest that conservationists, farmers, crop scientists and policy-makers collaborate to explore promising mechanisms.BP was funded by the Zukerman Research Fellowship in Global Food Security at King’s College, Cambridge.This is the accepted manuscript of a paper which was published in the Philosophical Transactions of the Royal Society B: Biological Sciences (B Phalan, R Green, A Balmford, Phil. Trans. R. Soc. B 2014, 369, 20120285

Crop expansion and conservation priorities in tropical countries

Expansion of cropland in tropical countries is one of the principal causes of biodiversity loss, and threatens to undermine progress towards meeting the Aichi Biodiversity Targets. To understand this threat better, we analysed data on crop distribution and expansion in 128 tropical countries, assessed changes in area of the main crops and mapped overlaps between conservation priorities and cultivation potential. Rice was the single crop grown over the largest area, especially in tropical forest biomes. Cropland in tropical countries expanded by c. 48,000 km2 per year from 1999–2008. The countries which added the greatest area of new cropland were Nigeria, Indonesia, Ethiopia, Sudan and Brazil. Soybeans and maize are the crops which expanded most in absolute area. Other crops with large increases included rice, sorghum, oil palm, beans, sugar cane, cow peas, wheat and cassava. Areas of high cultivation potential—while bearing in mind that political and socio-economic conditions can be as influential as biophysical ones—may be vulnerable to conversion in the future. These include some priority areas for biodiversity conservation in tropical countries (e.g., Frontier Forests and High Biodiversity Wilderness Areas), which have previously been identified as having ‘low vulnerability’, in particular in central Africa and northern Australia. There are also many other smaller areas which are important for biodiversity and which have high cultivation potential (e.g., in the fringes of the Amazon basin, in the Paraguayan Chaco, and in the savanna woodlands of the Sahel and East Africa). We highlight the urgent need for more effective sustainability standards and policies addressing both production and consumption of tropical commodities, including robust land-use planning in agricultural frontiers, establishment of new protected areas or REDD+ projects in places agriculture has not yet reached, and reduction or elimination of incentives for land-demanding bioenergy feedstock

Support amongst UK pig farmers and agricultural stakeholders for the use of food losses in animal feed.

While food losses (foods which were intended for human consumption, but which ultimately are not directly eaten by people) have been included in animal feed for millennia, the practice is all but banned in the European Union. Amid recent calls to promote a circular economy, we conducted a survey of pig farmers (n = 82) and other agricultural stakeholders (n = 81) at a UK agricultural trade fair on their attitudes toward the use of food losses in pig feed, and the potential relegalisation of swill (the use of cooked food losses as feed). While most respondents found the use of feeds containing animal by-products or with the potential for intra-species recycling (i.e. pigs eating pork products) to be less acceptable than feeds without, we found strong support (>75%) for the relegalisation of swill among both pig farmers and other stakeholders. We fit multi-hierarchical Bayesian models to understand people's position on the relegalisation of swill, finding that respondents who were concerned about disease control and the perception of the pork industry supported relegalisation less, while people who were concerned with farm financial performance and efficiency or who thought that swill would benefit the environment and reduce trade-deficits, were more supportive. Our results provide a baseline estimate of support amongst the large-scale pig industry for the relegalisation of swill, and suggest that proponents for its relegalisation must address concerns about disease control and the consumer acceptance of swill-fed pork

Walk on the Wild Side: Estimating the Global Magnitude of Visits to Protected Areas

How often do people visit the world’s protected areas (PAs)? Despite PAs covering one-eighth of the land and being a major focus of nature-based recreation and tourism, we don’t know. To address this, we compiled a globally-representative database of visits to PAs and built region-specific models predicting visit rates from PA size, local population size, remoteness, natural attractiveness, and national income. Applying these models to all but the very smallest of the world’s terrestrial PAs suggests that together they receive roughly 8 billion (8 x 109) visits/y—of which more than 80% are in Europe and North America. Linking our region-specific visit estimates to valuation studies indicates that these visits generate approximately US $600 billion/y in direct in-country expenditure and US$250 billion/y in consumer surplus. These figures dwarf current, typically inadequate spending on conserving PAs. Thus, even without considering the many other ecosystem services that PAs provide to people, our findings underscore calls for greatly increased investment in their conservation.This study was supported by The Natural Capital Project (http://www.naturalcapitalproject.org/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.This is the final published version. It first appeared at http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1002074

Walk on the wild side: estimating the global magnitude of visits to protected areas.

How often do people visit the world's protected areas (PAs)? Despite PAs covering one-eighth of the land and being a major focus of nature-based recreation and tourism, we don't know. To address this, we compiled a globally-representative database of visits to PAs and built region-specific models predicting visit rates from PA size, local population size, remoteness, natural attractiveness, and national income. Applying these models to all but the very smallest of the world's terrestrial PAs suggests that together they receive roughly 8 billion (8 x 109) visits/y-of which more than 80% are in Europe and North America. Linking our region-specific visit estimates to valuation studies indicates that these visits generate approximately US $600 billion/y in direct in-country expenditure and US$250 billion/y in consumer surplus. These figures dwarf current, typically inadequate spending on conserving PAs. Thus, even without considering the many other ecosystem services that PAs provide to people, our findings underscore calls for greatly increased investment in their conservation.This study was supported by The Natural Capital Project (http://www.naturalcapitalproject.org/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.This is the final published version. It first appeared at http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1002074

Local costs of conservation exceed those borne by the global majority

Cost data are crucial in conservation planning to identify more efficient and equitable land use options. However, many studies focus on just one cost type and neglect others, particularly those borne locally. We develop, for a high priority conservation area, spatial models of two local costs that arise from protected areas: foregone agricultural opportunities and increased wildlife damage. We then map these across the study area and compare them to the direct costs of reserve management, finding that local costs exceed management costs. Whilst benefits of conservation accrue to the global community, significant costs are borne by those living closest. Where livelihoods depend upon opportunities forgone or diminished by conservation intervention, outcomes are limited. Activities can be displaced (leakage); rules can be broken (intervention does not work); or the intervention forces a shift in livelihood profiles (potentially to the detriment of local peoples’ welfare). These raise concerns for both conservation and development outcomes and timely consideration of local costs is vital in conservation planning tools and processes

Land sparing to make space for species dependent on natural habitats and high nature value farmland.

Empirical evidence from four continents indicates that human food demand may be best reconciled with biodiversity conservation through sparing natural habitats by boosting agricultural yields. This runs counter to the conservation paradigm of wildlife-friendly farming, which is influential in Europe, where many species are dependent on low-yielding high nature value farmland threatened by both intensification and abandonment. In the first multi-taxon population-level test of land-sparing theory in Europe, we quantified how population densities of 175 bird and sedge species varied with farm yield across 26 squares (each with an area of 1 km2) in eastern Poland. We discovered that, as in previous studies elsewhere, simple land sparing, with only natural habitats on spared land, markedly out-performed land sharing in its effect on region-wide projected population sizes. However, a novel 'three-compartment' land-sparing approach, in which about one-third of spared land is assigned to very low-yield agriculture and the remainder to natural habitats, resulted in least-reduced projected future populations for more species. Implementing the three-compartment model would require significant reorganization of current subsidy regimes, but would mean high-yield farming could release sufficient land for species dependent on both natural and high nature value farmland to persist.Supported by a NERC CASE studentship to C.F

The biodiversity intactness index may underestimate losses.

The Biodiversity Intactness Index (BII) is a high-profile metric of an area’s average abundance of wild species relative to that in pre-modern times1 or in primary vegetation under current climatic conditions2. It has been endorsed by the Group on Earth Observations of the Biodiversity Observation Network, adopted by the Intergovernmental Platform on Biodiversity and Ecosystem Services as a "core" indicator of progress towards the Convention on Biological Diversity’s Aichi targets 12 and 14, and accepted by the Biodiversity Indicators Partnership as an indicator for Aichi target 5. We strongly support development of spatially-explicit indicators such as the BII, which can be used to prioritise areas for conservation interventions. However, it is important that the metric is as robust as possible, and we have noticed several unusual features of the BII that concern us

Changes in wild meat hunting and use by rural communities during the COVID‐19 socio‐economic shock

There is limited quantitative evidence of the effects of socio‐economic shocks on biological resource use. Focusing on wild meat hunting, a substantial livelihood and food source in tropical regions, we evaluated the impacts of the shock from Nigeria's coronavirus disease (COVID‐19) lockdown on species exploitation around a global biodiversity hotspot. Using a 3‐year quantitative dataset collected during and after the lockdown (covering 1008 hunter‐months) and matching by time of year, we found that successful hunting trip rates were more frequent during the lockdown, with a corresponding increase in the monthly number, mass, and value of animals caught. Moreover, hunters consumed a larger proportion of wild meat and sold less during lockdown, compared to non‐lockdown periods. These results suggest that local communities relied on wild meat to supplement reduced food and income during the lockdown, buffering the COVID‐19's socio‐economic shock. Our findings also indicate that wild species may be especially vulnerable to increased hunting pressure during socio‐economic shocks

Order of meals at the counter and distance between options affect student cafeteria vegetarian sales

Altering the order in which meals are presented at cafeteria counters has been proposed as a way of lowering meat consumption, but remains largely untested. To address this, we undertook two experimental studies involving 105,143 meal selections in the cafeterias of a British university. Placing vegetarian options first on the counter consistently increased their sales when choices were widely separated (>1.5 m; vegetarian sales as a percentage of total meal sales increased by 4.6 and 6.2 percentage points) but there was no evidence of an effect when the options were close together (<1.0 m). This suggests that order effects depend on the physical distance between options.This work was supported by E.E.G.’s NERC studentship grant number NE/L002507/1 and A.B.’s Royal Society Wolfson Research Merit awar